A woman injured three people and died of a self-inflicted gun shot wound at YouTube's headquarters in San Bruno, California on Tuesday, police say.

The female suspect who opened fire and is now dead was likely motivated by a domestic-related dispute, NBC News reports based on conversations with multiple senior law enforcement officials. Police have not released an official comment on the shooter's motives.

San Bruno Police Chief Ed Barberini said in a press conference that three victims were found on the scene with gunshot-related injuries, and one person was deceased with a possibly self-inflicted gunshot wound.

Three victims were taken to San Francisco General Hospital and a hospital administrator said in a press conference that one was in fair condition, one was in serious condition, and one patient was in critical condition.

Barberini said that at 12:46 PM San Bruno police received numerous phone calls about gunshots at YouTube's offices, which are separate from Google's main campus in Mountain View, and that police were on the scene within two minutes.

Several people identifying themselves as YouTube employees on Twitter posted about their experiences at the office:

Todd Sherman, who lists himself as a product manager at YouTube on his Twitter profile, wrote a series of tweets saying that he heard running while in a meeting and that when he exited the room, he heard that there was an active shooter.